Merge pull request #81 from koki-develop/list-themes-without-color

--list-themes output now has color disabled when redirecting

cmd/root.go

@@ -14,17 +14,18 @@ var rootCmd = &cobra.Command{
 	Short: "cat alternative written in Go",
 	Long:  "cat alternative written in Go.",
 	RunE: func(cmd *cobra.Command, args []string) error {
+		ist := term.IsTerminal(int(os.Stdout.Fd()))
+
 		switch {
 		case flagListLangs:
 			return gat.PrintLanguages(os.Stdout)
 		case flagListFormats:
 			return gat.PrintFormats(os.Stdout)
 		case flagListThemes:
-			return gat.PrintThemes(os.Stdout)
+			return gat.PrintThemes(os.Stdout, ist)
 		}
 
 		if strings.HasPrefix(flagFormat, "terminal") {
-			ist := term.IsTerminal(int(os.Stdout.Fd()))
 			if !ist {
 				if !flagForceColor {
 					flagTheme = "noop"

internal/gat/gat.go

@@ -287,42 +287,48 @@ func PrintFormats(w io.Writer) error {
 	return tw.Flush()
 }
 
-func PrintThemes(w io.Writer) error {
-	src := `package main
+func PrintThemes(w io.Writer, withColor bool) error {
+	if withColor {
+		src := `package main
 
 import "fmt"
 
 func main() {
 	fmt.Println("hello world")
 }`
 
-	for _, t := range styles.List() {
-		fmt.Fprintf(w, "\x1b[1m%s\x1b[0m\n\n", t)
+		for _, t := range styles.List() {
+			fmt.Fprintf(w, "\x1b[1m%s\x1b[0m\n\n", t)
 
-		g, err := New(&Config{
-			Language: "go",
-			Theme:    t,
-			Format:   "terminal256",
-		})
-		if err != nil {
-			return err
-		}
+			g, err := New(&Config{
+				Language: "go",
+				Theme:    t,
+				Format:   "terminal256",
+			})
+			if err != nil {
+				return err
+			}
 
-		buf := new(bytes.Buffer)
-		if err := g.Print(buf, strings.NewReader(src)); err != nil {
-			return err
-		}
+			buf := new(bytes.Buffer)
+			if err := g.Print(buf, strings.NewReader(src)); err != nil {
+				return err
+			}
 
-		// indent source
-		sc := bufio.NewScanner(buf)
-		for sc.Scan() {
-			if _, err := fmt.Fprintf(w, "\t%s\n", sc.Text()); err != nil {
+			// indent source
+			sc := bufio.NewScanner(buf)
+			for sc.Scan() {
+				if _, err := fmt.Fprintf(w, "\t%s\n", sc.Text()); err != nil {
+					return err
+				}
+			}
+
+			if _, err := fmt.Fprintln(w); err != nil {
 				return err
 			}
 		}
-
-		if _, err := fmt.Fprintln(w); err != nil {
-			return err
+	} else {
+		for _, t := range styles.List() {
+			fmt.Fprintln(w, t)
 		}
 	}